The invention pertains to power supplies for radio receiver circuits and the like that operate from an AC power line for deriving a DC voltage, and in particular to relatively inexpensive power supplies the voltage of which is readily switched on and off by an electronic switch capable of carrying current levels required by the radio receiver circuits. In known power supplies of this type the voltage from the primary AC power source is rectified by a pair of diodes or a diode bridge and filtered by a filter capacitor for reducing, but not totally removing, the ripple component of the rectified voltage. Ripple is an AC voltage component superimposed on the DC voltage. The filtered voltage may then be connected through the electronic switch to the various radio receiver stages. An additional electronic switch of low current capacity, such as multifunction switch of IC construction, may be employed to control the on-off operation of the principal switch. In circuits of this type, the magnitude of the ripple component is inversely related to the size and therefore the cost of the filter capacitor. Thus, the more expensive the capacitor, the more effective its filtering action and the smaller the ripple component. Conversely, to employ a relatively small, inexpensive filter capacitor will normally result in a filtered supply voltage with substantial ripple.